Every room in the Epilogue except for the last one has one or more objects that you can stand behind. Open the red journal on that screen and display its text. Stand behind one of the previously described objects. Note: If you open a green book, the red book will close and the text will disappear. Time manipulation must then be used to see all four new text.
Read the red book then find the hidden book with the scream.
Hit the switch so that the green platform goes up. Hit the switch to bring it back down. Stand on the red book. Use time manipulation to rewind so that the platform moves up with you on it. Run off the left of the platform. Look behind the rock for the sound.
Drop down, read the red book, then use time manipulation to rewind up to the left hand ledge. Walk behind the scenery until you hear the sound again.
Read the red book and walk into the next room. Stand on the left side of the green platform. Use time manipulation to rewind until you hear the green book close. Walk back into the third room. Move behind the rock.